One known type of information storage device is a disk drive device that uses magnetic media to store data and a movable read/write head that is positioned over the media to selectively read from or write to the disk.
FIGS. 1a and 1b illustrate a conventional disk drive device and show a magnetic disk 101 mounted on a spindle motor 102 for spinning the disk 101. A voice coil motor arm 104 carries a head gimbal assembly (HGA) 100 that includes a slider 103 incorporating a read/write head. A voice-coil motor (VCM, not labeled) is provided for controlling the motion of the motor arm 104 and, in turn, controlling the slider 103 to move from track to track across the surface of the disk 101, thereby enabling the read/write head to read data from or write data to the disk 101. In operation, a lift force is generated by the aerodynamic interaction between the slider 103, incorporating the read/write transducer, and the spinning magnetic disk 101. The lift force is opposed by equal and opposite spring forces applied by the HGA 100 such that a predetermined flying height above the surface of the spinning disk 101 is maintained over a full radial stroke of the motor arm 104.
Now referring to FIGS. 2a-2c, a HGA 100 of the conventional disk drive device of FIGS. 1a-1b comprises a load beam 106, a flexure 105 to connect with the flexure 105, and a slider 103 held on the flexure 105 at a distal end of the flexure 105. The HGA 100 is mounted to the motor arm 104. The load beam 106 has a dimple 107 integrally formed thereon to support the flexure 105 at a position corresponding to a center of the slider 103. During operation, the load forces coming from the HGA 100 are transferred to the center of the slider 103 via the dimple 107. The load forces are balanced by the opposite and equal lift force generated by aerodynamic interaction between the slider 103 and the spinning disk 101, thus making the slider 103 floating at a predefined flying height and maintaining a proper flying attitude, and realizing good data reading/writing operation for the disk drive.
It is desired that the dimple contact the flexure at a very accurate position which is exactly consistent with the center of the slider, and the contact area between the dimple and the flexure is as small as possible, so that the load forces can be uniformly transferred to the slider, thereby achieving optimal flying attitude and maintaining stable flying performance for the slider. Accordingly, with continuous miniaturization of the slider, the dimple should become small enough to contact the flexure at a position corresponding to the center of the slider fittingly and keep a very small contact area therebetween. However, in conventional HGA described above, since the dimple is integrally formed with the load beam, due to reasons such as die fabrication and dimension limitation of machine, it is difficult to manufacture a load beam with a size-reduced dimple incorporated thereon; consequently, when a slider of smaller form factor is mounted on the flexure, the dimple appears larger and larger with respect to the slider, and the contact area between the original dimple and size-reduced slider will be changed. This change in turn degrades flying attitude of the slider and finally influences badly the flying performance of the slider over the rotary disk, thereby deteriorating reading/writing capability of the disk drive unit when in use.
In addition, as shown in FIG. 2d, when in a conventional HGA assembling process, the load beam 106 and the flexure 105 are connected together in advance, and then the slider 103 is mounted to the flexure 105. Since presence of the dimple 107 between the load beam 106 and the flexure 105, the flexure 105 becomes tilting with respect to the load beam 106, and due to the tilt, the load beam 106 and the flexure 105 cannot be assembled with high positional precision. Consequently, when the slider is mounted on the flexure, the slider will have poor alignment with the dimple, thus further negatively affecting flying attitude and performance of the slider. Moreover, the tilt of the flexure relative to the load beam results in difficult in slider electrical bonding.
Thus, there is a need to provide an improved HGA that does not suffer from the above-mentioned drawbacks.